1. Field of the Invention
This invention relates generally to monitoring apparatus for mobile bulk material transport systems, and more particularly to apparatus for monitoring the level of grain as it is being loaded into the hopper(s) of a grain trailer.
2. Discussion of the Prior Art
In farming operations, grains such as corn, soybeans, wheat, etc. are commonly stored by the farmer in storage bins for later transport to a commercial elevator operation as market conditions may dictate. Exemplary storage bins may range in size from 15-54 feet in diameter and capacities up to nearly 66,000 bushels. When an appropriate shipment time is decided, the farmer must load a grain trailer from the storage bin, typically using an auger for moving the grain from the storage bin to the grain trailer.
Grain trailers may typically range in length from 30 feet to 50 feet and they include one or more hoppers. The trailers are typically 8 feet wide and may have sidewalls 6½ feet high. Arcuate gable rods span the width dimension of the trailer at spaced intervals along its length. The gable rods support a roll-back canvass cover which can be manipulated from the ground using a crank arrangement for operating a roller aligned with one sidewall of the trailer.
The trailer may have multiple axels and each hopper has an outlet at its bottom with a slidable door whereby a load can be emptied out the bottom of the trailer by sliding the door to its open position. The hoppers, of course, have inwardly and downwardly sloping inner sidewalls so as to funnel the load to the outlet.
When loading a trailer of the type described, the farmer will typically drive the semi-tractor used to pull the trailer such that a front most one of the hoppers is disposed beneath the storage bin unloading auger and will allow the grain to pour from the auger into the selected hopper. Because the farmer cannot directly view the grain level reached in the hoppers as they are being filled, he must periodically leave the tractor cab and mount a ladder on the trailer to peer through the open top of the trailer and observe so as to prevent overfilling and spillage. At an appropriate time, he must again drive the truck and trailer forward with respect to the auger so that a next hopper can be filled.
When it is recognized that the grain spilling into a trailer is a source of considerable dust, visually observing the load as it builds up in the hoppers is a dirty, distasteful job. Also, the need to repeatedly mount and dismount the ladder can become tiring and is a source of injury.
It can be seen, then, that a need exists for a way to monitor the filling of a grain trailer from a position within the truck's cab so that the farmer will know when it is necessary to move the trailer relative to the auger being used to load the trailer hopper(s). The present invention fulfills this need. It is also desirable that the farmer know the number of bushels he has loaded and the weight of the load to be taken to a commercial elevator for sale. The present invention provides this information, as well.